ABSTRACT
Isaiah Rogers' Boston Merchants Exchange and John S. Norris' Savannah Custom House (1846–52) share a unique, accordion-pleated, self-spanning wrought iron roof structure. While the Savannah Custom House has long been part of a National Historic Landmark District, it merits additional recognition for its bold structural design choices hidden within an exceptionally well-crafted, if stylistically conservative, monumental Greek Revival building. The Savannah Custom House remains in use as a Federal office building for the Immigration and Customs Enforcement and Department of Homeland Security. The Savannah Custom House roof also played a small, supporting role in an important symbolic event, leading towards the conclusion of the Civil War. Mullett seems not to have known that the Savannah roof, he deemed unique was closely related to an earlier, and once perhaps truly unique, roof on Isaiah Rogers' Boston Merchants Exchange, of 1840–43. Less than a dozen identified US iron roof structures, of which only two survive, pre-date the Savannah Custom House roof.
